30 GMAY ZU SOLMS-LAUBACir— MONOGRAPH OF THE ACETABULAEIE^. 



Prom the numerous hair-insertions there arise mostly clavate hair-knobs ; only the 

 middle ones appear to bear fully developed hair-tufts, which are very dense, but are 

 remarkable for their smallness and shortness. 



7. Coronal segments knob-shaped^ with ronndish upper surface and a circular 

 group of numerous hair-scars. 



15. AcETABrLAETA MoBii, n. sp. Minima, brevipedunculata. Disci radii vesiculares, 

 rotundato-obtusi, breves, septis tantum incrastatis. Coronse superioris processus 

 pilorum quinorum circiter seriem gerentes, verticem circularem circumdantem. 



Diminutive, short- stalked plant, with rugose stalk showing several diaphyses ; disc 

 terminal, with about 15 rays, rarely two above each other, and in such case without 

 any intervening hair-tufts ; sporangial rays inflated, arising from a basal portion 

 constricted on both sides, twice as long as broad, with obtuse rounded ends ; outer walls 

 of the rays not calcified, lateral walls united by strong calcification with nodular 

 emergences at the margin ; coronal knobs with roundish apex bearing a circle of about 

 five hair-insertions ; hair-tufts copiously branched, dense, but very short. 



Size : length of disc-rays 1*37-1'62 mm. ; breadth of coronal knobs radially measured 

 0-09 mm. (Hate IV. fig. 1.) 



Sab. On coral reefs, Mauritius {Mobius ; Pike, no. 168, lib. Kew, Hb. Brit. Mus.). 



This plant is nearly allied to the East Indian A. parvula, with which it completely 

 agrees in the mode of calcification and in habit, but is distinguished by the numerous 

 hair-scars of the coronal knobs forming a circular group. Mobius collected only one 

 plant and preserved it in spirits. It bore two caps above each other, which I have 

 not seen in the few specimens of Colonel Pike. It bore farther, on the hair-insertions, 

 very thick-walled short hair-rudiments, while on Pike's specimens only the hair-scars 

 were to be recognized, and these were very delicate. Whether there may be other 

 differences, farther investigation on the spot must decide. 



II. IIALICORYNE, Harv. 



Clavis analytica Specierum. 



1, Rami sporangiales patentes vel defiexi ; sporae liberse 1. ff^ Wriqhtii. 



2. Rami sporangiales suberecti ; sporse in massam irregularem conglutinatfe 2. H. spicata. 



The upright axis clothed with alternate differently formed whorls of branches, of 

 which the one consists of few branches — 8 — longish, tufted, branched hairs, the other 

 of mostly 16 branches, simple, longish ovate, pointed, almost pod-shaped vesicles, slio-htly 

 curved inwards above and completely free and fructifying in the adult plant. These 

 fertile branches, on the fructifying plant, inclined towards each other upwards and 

 separated from the small vestibule only by a basal partition-wall, bearing on the upper 

 side, not far from the base, a small protuberance which is furnished with one or two 

 diminutive, rudimentary hairs, reduced to an oval cellule. In the fertile state the upper 

 part of the vesicle is cut off by a thick partition-wall from the cylindrical basal portion 

 immediately in front of this hair-decked protuberance. In this so separated sporangial 



